Process of producing a mixture of camphene and isobornyl acetate from pinene hydrochlorid.



UNITED sirA nsr TENT OFFICE.

CARL RUDER, 0F WANDSBEK, GERMANY.

PROCESS OF PRODUCING A MIXTURE 0F CAMBHENE AND ISOBORNYL ACETATE FROM PINENE HYDROCHLORID.

No Drawing.

Specification of Letters Patent.

Application filed February 13, 1913. Serial No. 748,154.

Patented July 28, 1914..

To all 107mm it may concern Be it known that l. CARL Kenna, doctor of philosophy, manufacturer, a subject of the King of Bavaria, residing at YVandsbek, near Hamburg. in the State of Prussia. German Empire, have invented certain new and useful Ir provements in an Improved lrocess of Producing a Mixture of (hunphene and '[sobornyl Acetate from Pineue Hydrochlorid, of which the following is a specification. I

It has already been proposed to remove the chlorin from pincne hydrochlorid by heating it with acetate of lead in the presence of glacial acetic acid. This process, however, has proved itself completely un satisfactory and impractical, as the reactlon is not even approximately quantitative. Even after heating pinene h 'drochlorid for sixty hours with acetate of lead a product free from chlorin is not obtained. Further it is a well known fact that nincne hydrochlorid, by heating it with fatty acids and zinc salts of fatty acids, yields eamphenc and the iso-bornyl ester of the fatty acid. A great disadvantage of this process, however, is that the formationof zinc chlorid results in the condensation of much of the terpcne compounds and consequently in very ansatisfactorv yields. This objectionable con- (lensing effect of zinc chlorid becomes particularly noticeable when distilling ollf the fatty acid which has been used, so that it is practically impossible to recover the fatty acid. The oily mixture herein set-forth is to be considered as the substantial equivalent of pinene hydro-chlorid. This detrimental cflect of zinc chlorid may be avoided by adding to the mixture :1 second salt of the corresponding fatty acid, which reacts with the zinc chlorid present. forming the corresponding metallic chlorid, and regenerating the corresponding zinc salt of the fatty acid. Instead of a salt of a fatty acid, metallic oXids. for instance oxid of lead, may be used for the same purpose.

Experiments have shown that the chlorid of zinc which forms during the reaction is necessary in order to effect a complete removal of the chlorin. If for instance, the whole quantity of the fatty acid salt'is added at once, in spite of heating the mixture for a prolonged period, it is impossible to obtain a product free from chlorin. As, therefore,

the presence of zinc chlorid is necessary in order to effect the removal of the chlorin it is preferable to effect the same first and then add the second salt of the corresponding fatty acid, which renders the zinc chlorid harmless. After stirring the mixture for a short time distilled off Without affecting or impairin the yield in any way. The zinc chlori which forms during the reaction also, to some extent, exerts a condensing effect. In order to prevent this condensing action a PUI'tlOIlrfilbOllt half of the reruired uan tity-of the fatty'acid salt may e adde immediately at the commencement of the dechlorination process, whereas the remainder of said salt is added after the reaction is completed. The duration of the reaction under such circumstam'es is only slight] prolonged, while the yield becomes mm:

more satisfactory.

The sodium, potassium and lead salts of fatty acids form the most suitable addition slnce accompanied by the reformation of the corresponding zinc salt, sodium chlorid. potassium chlorid, and lead chlorid respec tively are formed, none of which have any condensing properties.

It is immaterial whether the metallic oxids or the formed (fatty acid) salts-the latter either hydrated or anhydrousare employed, as only the duration of the proc is varied in this way.

The product from which the chlorin has been removed consists of a mixture of camphene and iso-bornyl ester of the fatty acid. It is perfectly free from condensation products and is eminently suitable for the production of the iso-bornyl ester of the fatty acid.

Example.

(1.) 172 parts of pinene hydrochlorid are heated with 120 parts of anhydrous zinc acetate and 500 parts of glacial acetic acid, for -t hours to a temperature of 100 C. while being stirred. 98 parts of potassium acetate are then added and the glacial acetic acid is distilled off. The residue is washed with water, the result being a mixture of camphene and iso-bornyl ester which is perfectly free from ehlorin.

(2) 172 parts of yinene hydrochlorid, 45 parts of oxid of zinc, 40 parts of fused the surplus fatty acid may be' allowed to stand over night; the lever of terpene suited ontvby the sodium ehloriol formed by the reaction 1s removed and WflShd free from acetic acid. The gisciui acetic ecici and zinc acetate mixture is again ready for use after the section: chlorid ins been filtered oif.

(3) 172 parts 0:? pinene hydroch orni With 50 parts of zinc oxid an? 509 pans of ciai acetic acid are heated to hailing; for 1} hours nmier a reflux condenser, M33 parts of anhydrous lend acetate are nthiecl and the glacial acetic acid is: 6. the mixture being stirred meanwhile. i residue is treated with water and the oily mixture, which is perfectly free loin chlorin, is removed from the aqueous solu tion. This soiution after filteri g the lend, chlorid is evaporated to 1. anti the zinc acetate is thus recovered. :y for use (4%) 172 parts 0? pinsne hyclrochiorir are heated with 120 parts of anhydrous sine acetate and 500 parts of gieeiai iicetie acii'i "for four hours to 160 C, with constant stirrhag- 1153 parts of oxiti of ieecl are then i 3 a v i .4. added 21.110. the glacial acetic aid is hstiiled off the mixture being" stirrecl clurins the illsilliiitiillll'l. The fu'rtner treatment 1: s11niiar to that iiescriheei in Example 3.

Instead of acetic ZtClC'i. and the acetic Stilts, l

any other fatty ecici or its salts may of course-e be employed.

1 claim:

1. An iniproved'proecss for producing a mixture of camphene, and the isooorny] ester 01": fatty acid from'pinene l1 \'clrochioriii. consisting in' heating the same with efntty acid and the zinc salt of a fatty acid to eltect the removal of the chlorin and adding quantity of another salt of the corresponding fatty acid. of a metal WlL("" uhlorid has no condensing action on th June compounds, whereby all the zinc rlilorni formed during the re-ziction is con verteil into the zinc salt of the fatty acid with the fornmtiou of the corresponding chloricl of the added. metal.

[in improved pmcess for producing; a mixture oi camphene lllxl iso-hornyl acetate From pinene hydrochioritl consisting in limiting the same with acetic acid zinc acetate, and the acetate 01 1: metal whose chloritl has no condensing action on the terpcnc compounds, :1 portion of the latter suit being added before the coin]nencenient 

